Pitman-wheel.



J. H. BLAIR PITMAN WHEEL, APPLICATION FILED NOV-25.1914.

Patented Apr. 30, 1918.

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Be it knownthat 1,. JOHN; I-lnnnrBLAm,

a citizen of the United States, residing at Chico, in the county of Butte-and State of California, have invented 'certain new and." useful Improvements in Pitman-W'heels, of

which the following is a specificatioml This invention relates to transmission mechanism, and more particularly to that type of such mechanism knownas pitman or trammel wheels. 17

One object of theinvention istoprovide a trammel wheel having improved means for adjusting and guiding the sectors so .as to insure their proper relation. Another ob ject is to provide. an improved means of connecting the pitman rod with the slides whereby greater strengthis obtained.

With the above and other objects in view, and to improve generally upon the details of construction of such apparatus, the invention consists in the arrangement and combination of parts hereinafter described and claimed, and illustrated in the accompanying drawing, in which: a

Figure 1 isa front elevation of my improved trammel or pitman wheel, showing one end of the pitman rod connected therewith Fig. 2 is a section on the line 2-2 of Fig. 1, looking in the direction of the arrow;

and, v

Fig. 3 is a section on the line 3--3 of Fig. 1, looking in the direction of the arrow.

Referring to the drawings" in detail, my improved trammel wheel comprises. a disk 1, shown as solid, and preferably provided on its rear face with a central boss 2 in which the end of the driving shaft 3 is secured. Surrounding this disk is a rim 4,

which is rigidly secured to the disk in any desired way, {preferably by shrinking, after the manner 0 a tire. This rim is of greater width than the thickness of the disk, and

projects beyond the front face thereof a considerable distance, as clearly shown in Figs. 2 and 3. j

Mounted upon the front face of the disk 1 within the rim i are the four sectors or quadrants 5, spaced apart toform the intersecting grooves or guideways 6. The com bined thickness of these sectors and the disk is approximately equal to the width of the rim so that rinrgis substantially flush" withth'e facfe of the wheel on both sides.

The edges of the sectors 5 are under-cut mar r'ris rein.

JOHN HENRY BLAIR; ororrrco, cALIronnrA, Assienois or ONE-SIXTH To nnwenn cr UALIFORNIA,O1\TE-SIXTH ro rpwi nnvcriinivn, or oA LAnn, cALIronnI D one l Specification of Letters Patent. Patented- Apru30, 191%. :A neatioafi ancvember 25, 1914. swimwear/seas, i

to form grooves 7, adapted to "retain the,

slides 8 in the guidewayafsuclr slidesbeing L provided withcooperating ribsor flanges 8. Each slide 8 carr es a pivot'pin-9, jand the pins 9 extend through a boss 10, formed? on y preferably bi-furcated, as shownalt ,13 I'GCGIVB a ,W0Oden or other suitablelbar,

(not to be shown) which'extends to the device operated. A link 14: connects the pivot pins 9, and is secured in position by nuts 15,

be noted that the pivot pins 9 lie on a line at right angles to the axis of the pitman rod 12. Owing to this arrangement, it is not necessary that the pitman rod operate in a plane parallel with the wheel, as in prior devices, but such pitma-n rod may extend at an angle to the plane of the wheel without causing binding of the slides '8 in the guideways, suitable flexible joints being in this case provided at the points 9. This feati'ire is of particular importance in agricultural machines, such as reapers and mowers,'for which this trammel wheel 1s especially suitable.

lln order to permit adjustment of the secadvantage which may be mentioned. It will tor-shaped blocks 5, they are secured to the disk 1 by means of tap bolts 16, which are set into the blocks and work through elongated openings or slctsl'r", formed in the disk 1. It will be evident that by slightly loosening these bolts, the sectors may be adjusted as desired.

In order tofacilitate line adjustments, set screws 18 are provided, two for each sector. such screws extending through the rim i and bearing upon the outer edges of the sectors. It is apparent that by loosening the bolts 16, and then turning the screws 18,

the sectors 5 may be adjusted with great accuracy. I I

I also, provide means for maintaining the sectors in proper relation when being adjusted. To this end, there are formed on the meeting faces of the disk 1 and sectors, cooperating ribs and grooves as indicated at 19, and most clearly shown in Fig. As illustrated, the vribsare formed upon the disk and the grooves in the sectors, but obviously this arrangement might be reversed. 7 These radially disposed ribs and grooves insure thelsectors being held in true radial position at all times, and thus preserve absolute uniformity in the Width of the 'guideWays throughout their length;

This is essential to the successful Working of a device of this character.

In operation, asthe Wheel turns the slides 8 traverse the guidewaysfi in such a] manner as to cause two complete strokes of the pitman rod for every revolution of the Wheel.

What I claim is 1. The combination Witha tranimel Wheel,

Copies of this patent may be obtained for five cents each, by addressing the Commissioner Washington, D. G.

having intersecting guidcways, of a slide Working in each guideway, and a pitman rod having a Y-shaped end, each leg of Which is'connected with one of said slides.

2. The combination with a traniniel when] having intersecting guideways, of a slide Working in each gnidenay, a pitinan rod having a Y-shaped end, each leg oi which is pivoted to one of said slides, and a. link connecting such pivots to prevent spreading.

3. The combination with a trannnel wheel having intersecting gniden'ays. of a slide Working in each guiden'ay. and a pitman rod having a pivotal connection with said slides, the pivot points lying on a line substantially at right angles to the axis of said pitnian rod.

In testimony whereof I have allixed my signature, in presence of two witnesses.

JOHN HENRY BILUH. lVitnesses Lon Bonn,

SYDNEY S. Joiinsox.

of Patents, 

